Melt spinning method



June 15, 1954 P. KUMMEL 2,681,266 MELT SPINNING METHOD Filed Aug. 11, 1950 IN V EN T OR. F3404 K071014154 A rroaxvsy Patented June 15, 1954 2,681,266 MELT SPINNING METHOD Paul Kiimmel, Ems, Switzerland, assignor to Inventa A. G. fur Forschung und Patentver- Wertung, Lucerne, Switzerland Application August 11, 1950, Serial No. 178,788

1 Claim.

This invention relates to an improved method for molten flux spinning of polyamides.

More particularly the invention relates to a new method for molten flux spinning of plye-aminocaprolactam.

In the usual apparatus for molten spinning of polyamides, the polyamide is molten in a melting device, flows from there into a supply chamber (sump) and goes from there, via a pressure pump and a measuring pump to the spinning nozzle.

The entire device is surrounded by a heating jacket which heats the spinning mass to spinning temperature, i. e. to at least 40 C. above the melting point of the polyamide. In order to achieve this, the temperature of the heating jacket must lie -30 C. higher, or, in all, 60-70 C. above the melting point of the polyamides, and the same temperature obtains in the melting device.

sump of 550 com). Such a high extract content is not bearable for the production of fibers and threads; the monomers must be subsequently washed out and are lost in the wash-water.

It is necessary to make the sump larger than hitherto usual, so that the molten supply contained therein will be suflicient for spinning about 90 minutes, as only thus will the polymerisate be completely liquified at the low melting temperature.

The accompanying drawing shows schematically a spinning device for molten flux spinning according to the invention. Reference No. l is the heating jacket for the melting-device 2 as well as the supply chamber (sump) 3 for the flux supplied by the melting-device 2.

In the process according to the invention, the

data explain the process in invention:

the heating of the flux to spinning temperature, which is about 250 C., a further thermic reversion of 0.5%.

The process according to the invention, with a spinning extract of 3% as compared with the 5.9% of previous processes, exhibits the important advantage of a smaller reversion of water-soluble monomers of 2.9%, which, in the hitherto practiced processes are lost with the Wash-water.

I claim:

A method of spinning poly-E-amino caprolactam which comprises the steps of melting containing sub- References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,207,426 Bailey July 9, 1940 2,217,743 Greenewalt Oct. 15, 1940 2,241,321 Schlack May 6, 1041 2,514,189 Spencer et al July 4, 1950 2,515,136 Pigott July 11, 1950 

